I discovered Zimbra a day ago and I have to say I'm astonished by both the quality of the native AJAX based web client and the underlying Zimbra architecture.

However, I was wondering if anybody thinks AJAX client is suitable for mass deployment inside a larger company, as a replacement MS Outlook. I see AJAX client rather as a supplement for MS Outlook Web Access, therefore the question is - is it worth building native Zimbra client in some more powerful language say as a XUL/AJAX application running atop of XULRunner?

The port would be much easier than building the client up from scratch in C++/Java while the robustness seems better for me. One would even got benefits of either installing the client to local stations or running it from a server (XULRunner can AFAIK download and run XUL files from a remote server).
Also the UI would be better as XUL is more suitable for UI than css-styled xhtml.

Any comments from developers?